As the U.S. pursues a narrower approach to the Middle East, transatlantic relationships within NATO are shifting. Recent disputes over Washington’s handling of strikes in Iran, demands for allied help reopening the Strait of Hormuz, and repeated presidential comments suggesting a possible U.S. withdrawal have intensified European doubts about American reliability. Those doubts are pushing European capitals to prepare for a future in which they shoulder a far greater share of alliance leadership and military responsibility.
Frictions have accumulated over months. Actions and rhetoric that once would have been handled quietly among allies have instead provoked public rows: comments about annexing or acquiring territory, unilateral military moves without prior consultation, and Washington’s apparent willingness to reassess long-standing force postures in Europe. One concrete step that underscored those concerns was the Pentagon’s announcement to withdraw roughly 5,000 service members from Germany — about 14% of the U.S. presence there — a drawdown officials say reflects a review of force posture and conditions on the ground. While largely symbolic to some analysts, the move feeds a larger anxiety about what a sustained U.S. pullback would mean at a time when Russia remains Europe’s most significant military threat since the Cold War.
Trust between Washington and its NATO partners has eroded. Allies in Europe and Canada have publicly questioned whether the U.S. would come to their aid in a crisis, a question that would have been unthinkable in previous decades. That loss of confidence is reshaping defense planning: governments are reassessing procurement choices, accelerating capability-building programs, and rethinking the alliance’s command and force structure.
At the same time, Europe and Canada lack some critical high-end capabilities the United States supplies. Long-range precision strike, strategic air and sealift to move large forces and equipment quickly, and advanced intelligence, surveillance and reconnaissance systems are areas where NATO allies remain heavily dependent on U.S. assets. Building those capabilities domestically is possible but time-consuming: analysts estimate it will take roughly five to ten years to close major gaps, leaving a vulnerable window that adversaries could exploit.
The prospect of extended vulnerability is spurring change. Defense budgets across NATO rose sharply following earlier political pressures and Russia’s full-scale invasion of Ukraine; several countries now meet or exceed the long-established 2% of GDP defense benchmark, and leaders recently agreed on an ambitious new target of 5% of GDP by 2035. But increased spending must be converted into combat-relevant equipment and sustained readiness — not just headline figures — if Europe is to plug the operational shortfalls that would matter in a high-intensity conflict.
Practical steps are emerging. Germany has unveiled its most comprehensive post–Cold War military doctrine, naming Russia the main threat and laying out plans to significantly expand and modernize its armed forces with an eye to reinforcing NATO’s eastern flank. France is prepositioning carrier and naval assets in the region. Britain, while careful to distance itself from some U.S. policy choices, has signaled contributions to keeping sea lanes open. Meanwhile, smaller states on NATO’s eastern flank have already lifted spending to meet or exceed alliance pledges and are investing in capabilities aimed at deterring aggression.
That combination of renewed European ambition and continuing U.S. unpredictability points toward a new division of labor within NATO. Germany, France, the U.K., and increasingly Poland are seen as the likeliest core group to lead a stronger European pillar of the alliance. In practice, this would mean greater European operational autonomy for tasks ranging from regional deterrence to crisis response, while still relying on the U.S. for the highest-end capabilities — at least for now.
Experts caution that a fully independent European NATO is not an immediate or straightforward prospect. The United States remains indispensable in many respects, and legal and political barriers make a U.S. withdrawal complex. Even so, the perception that Washington might step back has accelerated planning in Europe and Canada: governments are deepening security ties with trusted partners, refining contingency plans, and investing in munitions, logistics, and command-and-control systems that would be required to act more independently.
The transition carries risks. Building complex military systems and industrial bases takes years and sustained political will; missteps could create a gap that adversaries exploit. Moreover, a stronger European defense posture born out of distrust could have ambiguous implications for transatlantic ties: it would strengthen NATO’s overall capacity, but a Europe acting from the assumption that it cannot rely on Washington could also widen political distance from the United States.
For now, the trajectory is clear: European capitals are moving from rhetoric to policy and procurement choices to hedge against the possibility that U.S. leadership within NATO will be less consistent than in past decades. Whether this produces a stable, more capable European pillar within a reconfigured transatlantic alliance — or generates new strategic fragmentation — will depend on how quickly allies translate higher spending into real combat capabilities, how the United States manages its NATO relationships going forward, and whether core European powers can coordinate effectively in both policy and military terms.